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authorIgor Pavlov <87184205+ip7z@users.noreply.github.com>2021-12-27 00:00:00 +0000
committerIgor Pavlov <87184205+ip7z@users.noreply.github.com>2022-03-18 15:35:13 +0500
commitf19f813537c7aea1c20749c914e756b54a9c3cf5 (patch)
tree816ba62ca7c0fa19f2eb46d9e9d6f7dd7c3a744d /C/7zCrcOpt.c
parent98e06a519b63b81986abe76d28887f6984a7732b (diff)
download7zip-21.07.tar.gz
7zip-21.07.tar.bz2
7zip-21.07.zip
'21.07'21.07
Diffstat (limited to '')
-rw-r--r--C/7zCrcOpt.c117
1 files changed, 117 insertions, 0 deletions
diff --git a/C/7zCrcOpt.c b/C/7zCrcOpt.c
new file mode 100644
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--- /dev/null
+++ b/C/7zCrcOpt.c
@@ -0,0 +1,117 @@
1/* 7zCrcOpt.c -- CRC32 calculation
22021-02-09 : Igor Pavlov : Public domain */
3
4#include "Precomp.h"
5
6#include "CpuArch.h"
7
8#ifndef MY_CPU_BE
9
10#define CRC_UPDATE_BYTE_2(crc, b) (table[((crc) ^ (b)) & 0xFF] ^ ((crc) >> 8))
11
12UInt32 MY_FAST_CALL CrcUpdateT4(UInt32 v, const void *data, size_t size, const UInt32 *table);
13UInt32 MY_FAST_CALL CrcUpdateT4(UInt32 v, const void *data, size_t size, const UInt32 *table)
14{
15 const Byte *p = (const Byte *)data;
16 for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
17 v = CRC_UPDATE_BYTE_2(v, *p);
18 for (; size >= 4; size -= 4, p += 4)
19 {
20 v ^= *(const UInt32 *)(const void *)p;
21 v =
22 (table + 0x300)[((v ) & 0xFF)]
23 ^ (table + 0x200)[((v >> 8) & 0xFF)]
24 ^ (table + 0x100)[((v >> 16) & 0xFF)]
25 ^ (table + 0x000)[((v >> 24))];
26 }
27 for (; size > 0; size--, p++)
28 v = CRC_UPDATE_BYTE_2(v, *p);
29 return v;
30}
31
32UInt32 MY_FAST_CALL CrcUpdateT8(UInt32 v, const void *data, size_t size, const UInt32 *table);
33UInt32 MY_FAST_CALL CrcUpdateT8(UInt32 v, const void *data, size_t size, const UInt32 *table)
34{
35 const Byte *p = (const Byte *)data;
36 for (; size > 0 && ((unsigned)(ptrdiff_t)p & 7) != 0; size--, p++)
37 v = CRC_UPDATE_BYTE_2(v, *p);
38 for (; size >= 8; size -= 8, p += 8)
39 {
40 UInt32 d;
41 v ^= *(const UInt32 *)(const void *)p;
42 v =
43 (table + 0x700)[((v ) & 0xFF)]
44 ^ (table + 0x600)[((v >> 8) & 0xFF)]
45 ^ (table + 0x500)[((v >> 16) & 0xFF)]
46 ^ (table + 0x400)[((v >> 24))];
47 d = *((const UInt32 *)(const void *)p + 1);
48 v ^=
49 (table + 0x300)[((d ) & 0xFF)]
50 ^ (table + 0x200)[((d >> 8) & 0xFF)]
51 ^ (table + 0x100)[((d >> 16) & 0xFF)]
52 ^ (table + 0x000)[((d >> 24))];
53 }
54 for (; size > 0; size--, p++)
55 v = CRC_UPDATE_BYTE_2(v, *p);
56 return v;
57}
58
59#endif
60
61
62#ifndef MY_CPU_LE
63
64#define CRC_UINT32_SWAP(v) ((v >> 24) | ((v >> 8) & 0xFF00) | ((v << 8) & 0xFF0000) | (v << 24))
65
66#define CRC_UPDATE_BYTE_2_BE(crc, b) (table[(((crc) >> 24) ^ (b))] ^ ((crc) << 8))
67
68UInt32 MY_FAST_CALL CrcUpdateT1_BeT4(UInt32 v, const void *data, size_t size, const UInt32 *table)
69{
70 const Byte *p = (const Byte *)data;
71 table += 0x100;
72 v = CRC_UINT32_SWAP(v);
73 for (; size > 0 && ((unsigned)(ptrdiff_t)p & 3) != 0; size--, p++)
74 v = CRC_UPDATE_BYTE_2_BE(v, *p);
75 for (; size >= 4; size -= 4, p += 4)
76 {
77 v ^= *(const UInt32 *)(const void *)p;
78 v =
79 (table + 0x000)[((v ) & 0xFF)]
80 ^ (table + 0x100)[((v >> 8) & 0xFF)]
81 ^ (table + 0x200)[((v >> 16) & 0xFF)]
82 ^ (table + 0x300)[((v >> 24))];
83 }
84 for (; size > 0; size--, p++)
85 v = CRC_UPDATE_BYTE_2_BE(v, *p);
86 return CRC_UINT32_SWAP(v);
87}
88
89UInt32 MY_FAST_CALL CrcUpdateT1_BeT8(UInt32 v, const void *data, size_t size, const UInt32 *table)
90{
91 const Byte *p = (const Byte *)data;
92 table += 0x100;
93 v = CRC_UINT32_SWAP(v);
94 for (; size > 0 && ((unsigned)(ptrdiff_t)p & 7) != 0; size--, p++)
95 v = CRC_UPDATE_BYTE_2_BE(v, *p);
96 for (; size >= 8; size -= 8, p += 8)
97 {
98 UInt32 d;
99 v ^= *(const UInt32 *)(const void *)p;
100 v =
101 (table + 0x400)[((v ) & 0xFF)]
102 ^ (table + 0x500)[((v >> 8) & 0xFF)]
103 ^ (table + 0x600)[((v >> 16) & 0xFF)]
104 ^ (table + 0x700)[((v >> 24))];
105 d = *((const UInt32 *)(const void *)p + 1);
106 v ^=
107 (table + 0x000)[((d ) & 0xFF)]
108 ^ (table + 0x100)[((d >> 8) & 0xFF)]
109 ^ (table + 0x200)[((d >> 16) & 0xFF)]
110 ^ (table + 0x300)[((d >> 24))];
111 }
112 for (; size > 0; size--, p++)
113 v = CRC_UPDATE_BYTE_2_BE(v, *p);
114 return CRC_UINT32_SWAP(v);
115}
116
117#endif